The day Dad's new computer arrives, Willy goes to the office with him to spend a happy day playing with the boxes, building everything from a plane to a circus. The resulting constructions are more the products of Boyd's (and Willy's) imagination than likely accomplishments of a preschooler, and are only occasionally linked to his real experiences (tired, he builds a house and falls asleep in it at the end of the day). Still, the make-believe adventures are nicely realized in Boyd's gentle, stylized art. (Picture book. 2-6)